394 



THE QUARTERLY REVIEW OF BIOLOGY 



Vest. 6 

 MD-Hdays. 



Wdo 

 MD--44days. 



Wild Fz 66 



"V" 



Wild Ft QQ 



V~*~^~ 



MD* 40 days. 



VeslFz 6 



Vest Fz 9 

 MD-13 days. 



Fig. 3. Pedigree Diagram Showing the Results in the First Two Generations of Crossing a Vestigial 

 Mutant with a Normal Wild Drosophila 



